<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>纵轴排列方式</title>
    <style type="text/css">
        #box{
            height: 700px;
            background: deeppink;
            display: flex;
            align-items: baseline;
            /* align-items: flex-start | flex-end | center | baseline | stretch;*/
        }
        .box1{
            font-size: 4px;
            height: 200px;
            width: 200px;
            flex: 1;
            background: black;
        }.box2{
            font-size: 12px;
             height: 200px;
             width: 200px;
             background: blue;
            flex: 3;
         }.box3{
                               font-size: 20px;
              height: 200px;
              width: 200px;
              background: red;
            flex: 2;
          }
    </style>
</head>
<body>
<div id="box">
    <div class="box1">div1</div>
    <div class="box2">div2</div>
    <div class="box3">div3</div>
</div>
</body>
</html>